Important: We highly recommend using the final URL suffix for custom non-3rd-party templates rather than merging with ClickGUARD's template.
Use the merge tool in Account Settings to get the merged template. You'll find it by first unchecking "I want ClickGUARD to automatically set Google Ads tracking template" option and clicking on the "Custom Template Merge Tool" button:
Then simply follow the on-screen instructions to get the merged template. Make sure to test the merged template in Google Ads after pasting it.